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piscidin 4, a novel member of the piscidin family of antimicrobial peptides.piscidins are linear, amphipathic, antimicrobial peptides (amps) with broad, potent, activity spectrum. piscidins and other members of the piscidin family appear to comprise the most common group of amps in teleost fish. all piscidins and related members of the piscidin family described to date are 18-26 amino acids long.we report here the isolation of a novel 5329.25 da, 44-residue (ffrhlfrgakaifrgarqgxrahkvvsryrnrdvpetdnnqeep) antimicrobial peptide from hybrid striped bass (morone chrysops fem ...200919266617
high-let ion radiolysis of water: oxygen production in tracks.it is known that molecular oxygen is a product of the radiolysis of water with high-linear energy transfer (let) radiation, a result that is of particular significance in radiobiology and of practical relevance in radiotherapy. in fact, it has been suggested that the radiolytic formation of an oxygenated microenvironment around the tracks of high-let heavy ions is an important factor in their enhanced biological efficiency in the sense that this may be due to an "oxygen effect" by o(2) produced ...200919267566
the effects of the bacterial interaction with visible-light responsive titania photocatalyst on the bactericidal performance.bactericidal activity of traditional titanium dioxide (tio2) photocatalyst is effective only upon irradiation by ultraviolet light, which restricts the potential applications of tio2 for use in our living environments. recently carbon-containing tio2 was found to be photoactive at visible-light illumination that affords the potential to overcome this problem; although, the bactericidal activity of these photocatalysts is relatively lower than conventional disinfectants. evidenced from scanning e ...200919272171
characterisation of early mucosal and neuronal lesions following shigella flexneri infection in human colon.shigella, an enteroinvasive bacteria induces a major inflammatory response responsible for acute rectocolitis in humans. however, early effect of shigella flexneri (s. flexneri) infection upon the human mucosa and its microenvironement, in particular the enteric nervous system, remains currently unknown. therefore, in this study, we sought to characterize ex vivo the early events of shigellosis in a model of human colonic explants. in particular, we aimed at identifying factors produced by s. fl ...200919274103
efficient synthesis of six tri- to hexasaccharide fragments of shigella flexneri serotypes 3a and/or x o-antigen, including a study on acceptors containing n-trichloroacetylglucosamine versus n-acetylglucosamine.six tri- to hexasaccharide fragments of the {2)-[alpha-d-glcp-(1-->3)]-alpha-l-rhap-(1-->2)-alpha-l-rhap-(1-->3)-[ac-->2]-alpha-l-rhap-(1-->3)-beta-d-glcpnac-(1-->}(n) polymer ([(e)ab(ac)cd](n)) were synthesized as their propyl glycosides. all targets share the (e)ab sequence. following a thorough investigation on the use of n-trichloroacetylglucosamine- versus n-acetylglucosamine-containing tri- and tetrasaccharide acceptors, the successful strategy was based on an efficient combination of the ...200919278208
foodborne outbreaks, austria 2007.in 2007 austria reported a total of 438 foodborne outbreaks affecting 1715 people, including 286 hospitalized patients and one death. salmonella spp. and campylobacter spp. accounted for 95% of all reported outbreaks. forty-eight (11%) of the 438 austrian outbreaks were acquired abroad. of the 390 domestically acquired foodborne outbreaks, bacterial infection caused 376, viruses (norovirus and 1-time hepatitis a virus) caused 11, and intoxications (staphylococcus aureus enterotoxins, alkaloid to ...200919280130
a food-borne outbreak of shigella sonnei gastroenteritis, austria, 2008.we report on the first foodborne outbreak of shigella sonnei described in austria. on july 14 2008, ages was informed of a cluster of 22 laboratory-confirmed cases of infection with s. sonnei restricted to public health district x in the province of salzburg. all cases had attended a youth-group trip to a small village in the province of tyrol from july 7 to july 9. an outbreak case among the trip participants was a person who (1) attended the trip and (2) fell ill with diarrhea in the period be ...200919280143
tri-county comprehensive assessment of risk factors for sporadic reportable bacterial enteric infection in children.the aim of this study was to determine risk factors for childhood sporadic reportable enteric infection (rei) caused by bacteria, specifically campylobacter, salmonella, escherichia coli o157, or shigella (rei-b).200919281302
application of a multiplex pcr assay for the detection of shigella, escherichia coli and shiga toxin-producing esch. coli in milk.a multiplex pcr (mpcr) assay using previously known genetic markers of shigella, escherichia coli and shiga-toxic esch. coli was standardized. uida gene was targeted for the common detection of esch. coli and shigella, whereas ipah and stx1 genes were used as markers for the detection of shigella and shiga-toxin producing strains, respectively. the standardized assays detected the target organism specifically and selectively. the mpcr developed by combining all the three reactions generated spec ...200919281632
genetics and virulence association of the shigella flexneri sit iron transport system.the sit-encoded iron transport system is present within pathogenicity islands in all shigella spp. and some pathogenic escherichia coli strains. the islands contain numerous insertion elements and sequences with homology to bacteriophage genes. the shigella flexneri sit genes can be lost as a result of deletion within the island. the formation of deletions was dependent upon reca and occurred at relatively high frequency. this suggests that the sit region is inherently unstable, yet sit genes ar ...200919289511
acute non-outbreak shigellosis: ten years experience in southern taiwan.we conducted a retrospective study of both the clinical and laboratory characteristics of shigellosis in southern taiwan.200919292940
the changing panorama of bacterial enteric infections.we studied the age-specific population-based incidence of bacterial enteric infections caused by shigella, salmonella and campylobacter, in jerusalem. during 1990-2008, 32,408 cases were reported (incidence rate 232.1/100,000 per annum). the patterns of shigella (47.4% of cases), salmonella (34.4%) and campylobacter (18.2%) infections evolved noticeably. campylobacter rates increased from 15.0 to 110.8/100,000 per annum. salmonella rates increased from 74.2 to 199.6/100,000 in 1995 then decrease ...200919296872
characterization of fluoroquinolone-resistant shigella flexneri in hangzhou area of china.the aim of this study was to characterize fluoroquinolone-resistant shigella and determine whether the qnr and aac(6')-ib-cr genes could contribute to sporadic shigellosis at the clinic in the hangzhou area of china.200919297378
serodiversity and antimicrobial resistance pattern of shigella isolates at gondar university teaching hospital, northwest ethiopia.the aims of this study were to determine the distribution of serogroups and serotypes as well as the antimicrobial resistance pattern of shigella isolates from gondar patients with acute diarrhea. a cross-sectional study was conducted from august 2006 to february 2008. stool specimens were received from study subjects and cultured. isolates were confirmed by biochemical and serological tests. the isolates were tested for antimicrobial susceptibility by the disc diffusion method. of the 1,200 sto ...200919305047
green banana reduces clinical severity of childhood shigellosis: a double-blind, randomized, controlled clinical trial.mature green banana (gb) fruit is rich in amylase-resistant starch that stimulates colonic production of short-chain fatty acids (referred to as fatty acid) and is useful in treating diarrheal diseases. we studied therapeutic effects of gb in childhood shigellosis by determining colonic fatty acid production in a double-blind, randomized, controlled, clinical trial.200919319017
structure and heme binding properties of escherichia coli o157:h7 chux.for many pathogenic microorganisms, iron acquisition from host heme sources stimulates growth, multiplication, ultimately enabling successful survival and colonization. in gram-negative escherichia coli o157:h7, shigella dysenteriae and yersinia enterocolitica the genes encoded within the heme utilization operon enable the effective uptake and utilization of heme as an iron source. while the complement of proteins responsible for heme internalization has been determined in these organisms, the f ...200919319934
surveillance of antibiotic susceptibility patterns among shigella sonnei strains isolated in belgium during the 18-year period 1990 to 2007.this study was conducted to determine the frequency and pattern of antimicrobial susceptibility of shigella sonnei, the predominant species causing shigellosis in belgium. between 1990 and 2007, a total of 7,307 strains, mainly (98.2%) isolated from stools, were diagnosed by peripheral laboratories before being confirmed as shigella strains by serotyping by the national reference center of salmonella and shigella. a significant increase in resistances to tetracycline, streptomycin, trimethoprim, ...200919321731
antimicrobial activity of the methanolic extract and compounds from morus mesozygia stem bark.this study was aimed at investigating the antimicrobial activity of the methanolic extract (mmb) and compounds isolated from the stem bark of morus mesozygia, namely 3beta-acetoxyurs-12-en-11-one (1), moracin q (2), moracin t (3), artocarpesin (4), cycloartocarpesin (5), moracin r (6), moracin u (8), moracin c (9), and moracin m (10).200919450674
diagnosis and treatment of acute or persistent diarrhea.studies of microbial pathogens and the toxins they produce are important for determining the mechanisms by which they cause disease and spread throughout a population. some bacteria produce secretory enterotoxins (such as cholera toxin or the heat-labile or stable enterotoxins produced by escherichia coli) that invade cells directly. others invade cells or produce cytotoxins (such as those produced by shigella, enteroinvasive e coli, or clostridium difficile) that damage cells or trigger host re ...200919457416
molecular typing methodologies for microbial source tracking and epidemiological investigations of gram-negative bacterial foodborne pathogens.gram-negative bacterial foodborne pathogens are a worldwide cause of morbidity and mortality. the ability to carry out epidemiological investigations to determine the primary sources of bacterial contamination is important to improve public health. multiple methods are available for bacterial source tracking and to determine the distribution of pathogens isolated from sick patients. the molecular based typing methods available fall into three general categories: those based on restriction analys ...200919460308
metabolic control through ornithine and uracil of epithelial cell invasion by shigella flexneri.this paper shows that compounds in defined growth media strongly influence the expression of the effectors of virulence in the human invasive pathogen shigella flexneri. ornithine in conjunction with uracil reduces the haemolytic ability of wild-type cultures more than 20-fold and the expression of the type iii secretion system more than 8-fold, as monitored by an mxic : : lacz transcriptional reporter. mxic gene expression is further decreased by the presence of methionine or branched-chain ami ...200919460819
design, synthesis, and immunochemical characterization of a chimeric glycopeptide corresponding to the shigella flexneri y o-polysaccharide and its peptide mimic mdwnmhaa.two glycopeptide chimeras corresponding to the shigella flexneri y o-polysaccharide and its peptide mimic were designed in an attempt to improve the binding affinity by increasing the entropy of binding relative to the original octapeptide mimic of the o-polysaccharide. the design was based on the x-ray crystal structures of a monoclonal antibody sya/j6 in complex with its cognate ligands, a pentasaccharide corresponding to the s. flexneri y o-polysaccharide and the octapeptide mimic, mdwnmhaa. ...200919467535
rapid detection of intestinal pathogens in fecal samples by an improved reverse dot blot method.to develop a new, rapid and accurate reverse dot blot (rdb) method for the detection of intestinal pathogens in fecal samples.200919469006
incidence of multiple antibiotic resistant gram-negative bacteria isolated from surface and underground water sources in south western region of nigeria.in most rural and urban settlements, particularly in nigeria, wells, spring, streams or rivers and lakes serves as major sources of water supply for drinking and other domestic purposes. unfortunately, many of the available water sources are not potable without some form of treatment which is seldom available in most settings. the use of untreated surface water sources for drinking and for domestic purposes remains a major threat to public health as these could serve as reservoirs the for transf ...200919474486
involvement of rna-binding protein hfq in the osmotic-response regulation of inve gene expression in shigella sonnei.the expression of type iii secretion system (ttss) in shigella is regulated in response to changes in environmental osmolarity and temperature. temperature-dependent regulation of virf, the master regulator of ttss synthesis, is believed to occur at the transcriptional level. we recently demonstrated, however, that ttss synthesis also involves post-transcriptional regulation of the synthesis of inve, a target of virf and key regulator of ttss synthesis. the mrna levels of inve (virb) are stable ...200919476612
ipab-ipgc interaction defines binding motif for type iii secretion translocator.the delivery of virulence factors into host cells through type iii secretion systems is essential for enterobacterial pathogenesis. molecular chaperones bind specifically to virulence factors in the bacterial cytosol before secretion. invasion plasmid gene c (ipgc) is a chaperone that binds 2 essential virulence factors of shigella: invasion plasmid antigens (ipa) b and c. here, we report the crystal structure of ipgc alone and in complex with the chaperone binding domain (cbd) of ipab. the chap ...200919478065
comparison of acute bloody and watery diarrhea: a case control study.the clinical and laboratory findings of 290 cases of bloody diarrhea who presented to the department of diarrhea training and treatment between june 1998 and may 2002 were investigated, and compared to those of two consecutive cases who had watery diarrhea. the bloody diarrhea group had higher mean age, higher frequencies of diarrhea, lower frequencies of vomiting, and shorter durations of diarrhea at the time of admission as compared to the watery diarrhea group. the number of cases using antib ...200919480324
laboratory-acquired infections.laboratory-acquired infections due to a wide variety of bacteria, viruses, fungi, and parasites have been described. although the precise risk of infection after an exposure remains poorly defined, surveys of laboratory-acquired infections suggest that brucella species, shigella species, salmonella species, mycobacterium tuberculosis, and neisseria meningitidis are the most common causes. infections due to the bloodborne pathogens (hepatitis b virus, hepatitis c virus, and human immunodeficiency ...200919480580
reactive arthritis: clinical aspects and medical management.reactive arthritis (rea) is an inflammatory arthritis that arises after certain gastrointestinal or genitourinary infections, representing a classic interplay between host and environment. it belongs to the group of arthritidies known as the spondyloarthropathies. the classic syndrome is a triad of symptoms, including the urethra, conjunctiva, and synovium; however, the majority of patients do not present with this triad. diagnostic criteria for rea exist, but data suggest new criteria are neede ...200919480995
analytical comparison of nine pcr primer sets designed to detect the presence of escherichia coli/shigella in water samples.the analytical performance of 9 different pcr primer sets designed to detect escherichia coli and shigella in water has been evaluated in terms of ubiquity, specificity, and analytical detection limit. of the 9 pcr primer sets tested, only 3 of the 5 primer sets targeting uida gene and the primer set targeting tuf gene amplified dna from all e. coli strains tested. however, of those 4 primer sets, only the primer set targeting the tuf gene also amplified dna from all shigella strains tested. for ...200919482328
protein interaction platforms: visualization of interacting proteins in yeast.here we describe the protein interaction platform assay, a method for identifying interacting proteins in saccharomyces cerevisiae. this assay relies on the reovirus scaffolding protein microns, which forms large focal inclusions in living cells. when a query protein is fused to microns and potential interaction partners are fused to a fluorescent reporter, interactors can be identified by screening for yeast that display fluorescent foci.200919483691
lack of antimicrobial activity by the antiretroviral drug nevirapine against common bacterial pathogens. 200919487448
bacteria hijack integrin-linked kinase to stabilize focal adhesions and block cell detachment.the rapid turnover and exfoliation of mucosal epithelial cells provides an innate defence system against bacterial infection. nevertheless, many pathogenic bacteria, including shigella, are able to surmount exfoliation and colonize the epithelium efficiently. here we show that the shigella flexneri effector ospe (consisting of ospe1 and ospe2 proteins), which is highly conserved among enteropathogenic escherichia coli, enterohaemorrhagic e. coli, citrobacter rodentium and salmonella strains, rei ...200919489119
laboratory diagnosis of infectious diarrhoea syndrome; a three years study in two hospitals of infectious diseases.infectious diarrhoea is a syndrome caused by a variety of bacterial, viral and parasitic organisms which represents a major cause of morbidity and mortality all over the world. the wide diversity of etiological agents impairs the surveillance and the diagnosis and affects the correct treatment applied to reduce the long-term complications. besides well known enteric pathogens such as salmonella, shigella and yersinia, a high number of emergent and re-emergent aetiologies are now recognised to be ...200920361527
pcr targeting of antibiotic resistant bacteria in public drinking water of lahore metropolitan, pakistan.to investigate the prevalence of kanamycin (kan) and ampicillin (amp) resistant bacteria in public drinking water.200920337218
an urban, water-borne outbreak of diarrhoea and shigellosis in a district town in eastern india.in september 2007, the gayeshpur municipality reported a cluster of cases with diarrhoea. we aimed to identify the causative agent and the source of the disease.200920334044
acute gastrointestinal illness in new zealand: information from a survey of community and hospital laboratories.to describe and quantify laboratory testing of faecal samples for enteric pathogens as a component of the reporting pyramid of acute gastrointestinal illness (agi) in new zealand.200920148044
screening of antibacterial potentials of some medicinal plants from melghat forest in india.cyperus rotundus, caesalpinia bonducella, tinospora cordifolia, gardenia gummifera, ailanthus excelsa, acacia arabica, embelia ribes and ventilago maderspatana from melghat forest were screened for their antibacterial potential against escherichia coli, staphylococcus aureus, klebsiella pneumoniae, proteus vulgaris, salmonella typhi, shigella flexneri, salmonella paratyphi, salmonella typhimurium, pseudomonas aeruginosa, enterobacter aerogenes by disc diffusion method. out of these medicinal pla ...200920448847
sporadic paediatric diarrhoeal illness in urban and rural sites in nyanza province, kenya.investigate differences in the infectious aetiology, health seeking behaviour, and provider practices with regard to diarrhoeal illness among children presenting to urban versus rural clinics in western kenya.200920575313
association of water-borne diseases morbidity pattern and water quality in parts of ibadan city, nigeria.occurrence of diarrhoea and other water-borne diseases in cities of developing countries has been on the increase over the decades largely due to unsafe water, inadequate sanitation and poor hygiene among human population. this study examined the relationship between the spatial pattern of water-borne diseases vis-a-vis water quality in parts of ibadan city in nigeria. data on 1334 cases of various water-borne diseases was collected from eight public hospitals with catchments covering the study ...200920734698
prevalence and antimicrobial resistance of diarrheagenic escherichia coli and shigella species associated with acute diarrhea in tehran, iran.a study was performed to determine the prevalence and antimicrobial resistance of shigella species and diarrheagenic escherichia coli isolates cultured from patients with acute diarrhea in tehran, iran. between may 2003 and may 2005, 1120 diarrheal specimens were collected and assayed for bacterial enteropathogens by conventional and molecular methods. etiological agents were isolated from 564 (50.3%) specimens, and included 305 (54%) e coli, 157 (27.8%) shigella species, and 102 (18%) from othe ...200920808457
[shigella strategy for host defense and mucosal infection]. 200921089529
antibacterial, antifungal and cytotoxic activities of amblyone isolated from amorphophallus campanulatus.to assess the in vitro antibacterial, antifungal and cytotoxic activities of amblyone, a triterpenoid isolated from amorphophallus campanulatus (roxb).200821264161
synthesis, antimicrobial and antiinflammatory activity of 2,5-disubstituted-1,3,4-oxadiazoles.in the present study, 2,5-disubstituted-1,3,4-oxadiazoles (3a-o) have been synthesized by the condensation of 4-methoxybenzohydrazide (1) with different aromatic acids (2a-o) in presence of phosphoryl chloride. the structural assignment of this compound (3a-o) has been made on the basis of elemental analysis, uv, ir, (1)h nmr and mass spectral data. the synthesized compounds were screened for their in vitro growth inhibiting activity against different strains of bacteria and fungi viz., staphylo ...200820390080
intestinal bacterial and parasitic infections among food handlers in a tertiary care hospital of north india.intestinal infection is still an important public health problem in developing countries like india. food handlers may be infected by a wide range of enteropathogens and have been implicated in the transmission of many infections to the public in the community and to patients in hospitals.200819323089
antibacterial antibodies for some enterobacteria in sera of patients with reactive arthritis and other rheumatoid diseases.the presence of the specific antibodies for some enterobacteria--yersinia, salmonella and shigella was investigated in patients hospitalized in the period 2000-2007 with reactive arthritis and other rheumatoid diseases. the antibacterial antibodies in the diagnosis titres were found in 172 out of 1102 (15.6%) patients. increased antibodies levels to yersinia were detected in the sera from 113 (65.7%) of the 172 patients, for shigella in 47 (27.3%) and for salmonella in 12 (7.0%) cases. from all ...200819284164
interactions of the intestinal epithelium with the pathogen and the indigenous microbiota: a three-way crosstalk.the mucosal surfaces of the gastrointestinal tract harbor a vast number of commensal microbiota that have coevolved with the host, and in addition display one of the most complex relationships with the host. this relationship affects several important aspects of the biology of the host including the synthesis of nutrients, protection against infection, and the development of the immune system. on the other hand, despite the existence of several lines of mucosal defense mechanisms, pathogenic org ...200819259328
microbiological quality and safety of rastrineobola argentea retailed in kisumu town markets, kenya.to investigate faecal contamination and safety of rastrineobola argentea sold in retail markets in kisumu town.200819537428
safety and colonization of two novel virg(icsa)-based live shigella sonnei vaccine strains in rhesus macaques (macaca mulatta).shigella are gram-negative bacterium that cause bacillary dysentery (shigellosis). symptoms include diarrhea and discharge of bloody mucoid stools, accompanied by severe abdominal pain, nausea, vomiting, malaise, and fever. persons traveling to regions with poor sanitation and crowded conditions become particularly susceptible to shigellosis. currently a vaccine for shigella has not been licensed in the united states, and the organism quickly becomes resistant to medications. during the past 10 ...200819793462
comparative study of leaf and stem bark extracts of parkia biglobosa against enterobacteria.hydroethanolic and aqueous extracts of leaf and stem bark of parkia biglobosa (jacq) benth. (mimosaceae) were tested against clinical isolates escherichia coli, salmonella typhi, shigella dysenteriae and enterococcus faecalis, and corresponding collection strains e. coli cip 105 182, salmonella enterica cip 105 150, shigella dysenteriae cip 54-51 and enterococcus faecalis cip 103 907. discs of gentamicin, a broad spectrum antibiotic were used as positive controls. the results showed that all the ...200820161943
antimicrobial activity of various extracts of ocimum basilicum l. and observation of the inhibition effect on bacterial cells by use of scanning electron microscopy.the antimicrobial activities of chloroform, acetone and two different concentrations of methanol extracts of ocimum basilicum l. were studied. these extracts were tested in vitro against 10 bacteria and 4 yeasts strains by the disc diffusion method. the results indicated that the methanol extracts of o. basilucum exhibited the antimicrobial activity against tested microorganisms. while the chloroform and acetone extracts had no effect, the methanol extracts showed inhibition zones against strain ...200820161958
contamination of herbal medicinal products marketed in kaduna metropolis with selected pathogenic bacteria.the study aimed to evaluate the bacterial contamination of powdered herbal medicinal preparations sourced from identified herbal retail outlets in different parts of kaduna metropolis. the assessments of the contamination of the herbal products were carried out using standard procedures: total aerobic bacterial plate count, measurement of some physical parameters, isolation and characterization of selected bacterial pathogens etc. the results showed that out of a total of 150, 70 (46.67%) herbal ...200820162044
differential activation of human tlr4 by escherichia coli and shigella flexneri 2a lipopolysaccharide: combined effects of lipid a acylation state and tlr4 polymorphisms on signaling.the lipid a of lps activates tlr4 through an interaction with myeloid differentiation protein-2 (md-2) and the degree of lipid a acylation affects tlr4 responsiveness. two tlr4 single nucleotide polymorphisms (asp299gly and thr399ile) have been associated with lps hyporesponsiveness. we hypothesized that the combination of hypoacylation and these single nucleotide polymorphisms would exhibit a compounded effect on tlr4 signaling. hek293t transfectants expressing wild-type or polymorphic tlr4 wer ...200818178854
nlrx1 is a mitochondrial nod-like receptor that amplifies nf-kappab and jnk pathways by inducing reactive oxygen species production.nod-like receptors (nlrs) are a family of intracellular sensors of microbial- or danger-associated molecular patterns. here, we report the identification of nlrx1, which is a new member of the nlr family that localizes to the mitochondria. nlrx1 alone failed to trigger most of the common signalling pathways, including nuclear factor-kappab (nf)-kappab- and type i interferon-dependent cascades, but could potently trigger the generation of reactive oxygen species (ros). importantly, nlrx1 synergis ...200818219313
regulation of expression and secretion of nleh, a new non-locus of enterocyte effacement-encoded effector in citrobacter rodentium.together with enterohemorrhagic escherichia coli and enteropathogenic escherichia coli, citrobacter rodentium is a member of the attaching-and-effacing (a/e) family of bacterial pathogens. a/e pathogens use a type iii secretion system (t3ss) to translocate an assortment of effector proteins, encoded both within and outside the locus of enterocyte effacement (lee), into the colonized host cell, leading to the formation of a/e lesions and disease. here we report the identification and characteriza ...200818223087
the origin of a novel gene through overprinting in escherichia coli.overlapped genes originate by a) loss of a stop codon among contiguous genes coded in different frames; b) shift to an upstream initiation codon of one of the contiguous genes; or c) by overprinting, whereby a novel open reading frame originates through point mutation inside an existing gene. although overlapped genes are common in viruses, it is not clear whether overprinting has led to new genes in prokaryotes.200818226237
cytoplasmic targeting of ipac to the bacterial pole directs polar type iii secretion in shigella.type iii secretion (t3s) systems are largely used by pathogenic gram-negative bacteria to inject multiple effectors into eukaryotic cells. upon cell contact, these bacterial microinjection devices insert two t3s substrates into host cell membranes, forming a so-called 'translocon' that is required for targeting of type iii effectors in the cell cytosol. here, we show that secretion of the translocon component ipac of invasive shigella occurs at the level of one bacterial pole during cell invasio ...200818188151
bacterial actin assembly requires toca-1 to relieve n-wasp autoinhibition.actin polymerization in the mammalian cytosol can be locally activated by mechanisms that relieve the autoinhibited state of n-wasp, an initiator of actin assembly, a process that also requires the protein toca-1. several pathogenic bacteria, including shigella, exploit this host feature to infect and disseminate efficiently. the shigella outer membrane protein icsa recruits n-wasp, which upon activation at the bacterial surface mediates localized actin polymerization. the molecular role of toca ...200818191793
antibacterial activities and cytotoxicity of terpenoids isolated from spirostachys africana.spirostachys africana sond. stem bark is used traditionally for the treatment of diarrhoea and dysentery in limpopo province of south africa. bioassay-guided fractionation of ethanolic extract from bark of spirostachys africana led to the isolation of four known compounds, two triterpenoids, compound 1 [d-friedoolean-14-en-oic acid (3-acetyl aleuritolic acid)] and compound 2 (lupeol), and two diterpenes, compound 3 [ent-2,6alpha-dihydroxy-norbeyer-1,4,15-trien-3-one (diosphenol 2)] and compound ...200818191928
the chaperone ipgc copurifies with the virulence regulator mxie.the expression of a subset of shigella flexneri virulence genes is dependent upon a cytoplasmic chaperone, ipgc, and an activator from the arac/xyls family, mxie. in this paper, we report that the chaperone forms a specific and stable heteromer with mxie.200818192384
role and regulation of iron-sulfur cluster biosynthesis genes in shigella flexneri virulence.shigella flexneri, a causative agent of bacterial dysentery, possesses two predicted iron-sulfur cluster biosynthesis systems called suf and isc. s. flexneri strains containing deletion mutations in the entire suf operon (ur011) or the iscsua genes (ur022) were constructed. both mutants were defective in surviving exposure to oxidative stress. the suf mutant showed growth that was comparable to that of the parental strain in both iron-replete and iron-limiting media; however, the isc mutant show ...200818195027
evaluation of faecal occult blood test and lactoferrin latex agglutination test in screening hospitalized patients for diagnosing inflammatory and non-inflammatory diarrhoea in dhaka, bangladesh.inflammatory diarrhoea (id) resulting from shigella, salmonella, campylobacter and entamoeba histolytica requires specific diagnosis for therapy. differentiation between id and non-inflammatory diarrhoea (nid) is often not clinically possible. a faecal occult blood test (fobt) correlates with faecal leucocytes. lactoferrin indicates an inflammatory process as a marker for faecal leucocytes. we evaluated diagnostic values of lactoferrin latex agglutination test (lt) either alone or in combination ...200818196900
new information about pediatric foodborne infections: the view from foodnet.diarrheal illness is a significant burden to children and their parents. recent studies describing the etiologic agents that cause diarrheal illness and examining the risk factors for the most common bacterial enteric pathogens are presented.200818197044
molecular pathogenesis of shigella spp.: controlling host cell signaling, invasion, and death by type iii secretion.shigella spp. are gram-negative pathogenic bacteria that evolved from harmless enterobacterial relatives and may cause devastating diarrhea upon ingestion. research performed over the last 25 years revealed that a type iii secretion system (t3ss) encoded on a large plasmid is a key virulence factor of shigella flexneri. the t3ss determines the interactions of s. flexneri with intestinal cells by consecutively translocating two sets of effector proteins into the target cells. thus, s. flexneri co ...200818202440
a comparison of self-reported joint symptoms following infection with different enteric pathogens: effect of hla-b27.we conducted a case-case comparison study to estimate the attack-rate of reactive joint pain (jprea) following intestinal infections, and evaluated whether the susceptibility and severity of joint symptoms was associated with the tissue-type hla-b27.200818203313
phase 1 clinical trial of live attenuated shigella dysenteriae type-1 deltaicsa deltaent deltafep deltastxa:hgr oral vaccine sc599 in healthy human adult volunteers.twenty-eight adults received between 10(2) and 10(8)colony forming units of live shigella dysenteriae type-1 vaccine sc599, attenuated by deletion of invasion (icsa), iron chelation (ent, fep) and shiga toxin a-subunit (stxa) genes, followed by ciprofloxacin on day 4. dose-independent diarrhea or change in bowel habit was seen in 3 subjects, without dysentery, vaccinaemia or serious adverse events. hematology and biochemical parameters were unchanged. doses of 10(5) or greater induced dose-indep ...200818207287
a functional genomic yeast screen to identify pathogenic bacterial proteins.many bacterial pathogens promote infection and cause disease by directly injecting into host cells proteins that manipulate eukaryotic cellular processes. identification of these translocated proteins is essential to understanding pathogenesis. yet, their identification remains limited. this, in part, is due to their general sequence uniqueness, which confounds homology-based identification by comparative genomic methods. in addition, their absence often does not result in phenotypes in virulenc ...200818208325
nitrate and bacterial contamination in well waters in vinh phuc province, vietnam.measurements were made of the nitrate concentration and bacterial contamination of groundwater samples taken from both dug wells and bores in the commune of hop thinh', in the administrative district of vinh phuc, vietnam. a significant number (18%) of samples had nitrate concentrations in excess of the who guideline value for drinking water of 50 mg l(-1), with a higher proportion in the dug wells (29%) than the bores (3.8%). high concentrations of thermotolerant coliforms were found in many of ...200818209289
selection and validation of a multilocus variable-number tandem-repeat analysis panel for typing shigella spp.the shigella genus has historically been separated into four species, based on biochemical assays. the classification within each species relies on serotyping. recently, genome sequencing and dna assays, in particular the multilocus sequence typing (mlst) approach, greatly improved the current knowledge of the origin and phylogenetic evolution of shigella spp. the shigella and escherichia genera are now considered to belong to a unique genomospecies. multilocus variable-number tandem-repeat (vnt ...200818216214
timeliness of enteric disease surveillance in 6 us states.we reviewed timeline information for a sample of salmonella spp., shigella spp., campylobacter spp., and escherichia coli o157:h7 cases and all confirmed foodborne outbreaks reported in 6 states during 2002. increasing the timeliness of case follow-up, molecular subtyping, and linkage of results are critical to reducing delays in the investigation of foodborne outbreaks.200818258128
[shigella spp infections in children living in the metropolitan region, chile, during summer of 2004-2005].shigella spp is a frequent cause of diarrhea in children. antimicrobials decrease the duration of diarrhea and pathogen excretion. however, the increasing resistance limits their therapeutic value.200818259649
[shigellosis outbreak with 146 cases related to a fair].on september 3, 2005, the ciudad real public health service (spain) received a report of 20 cases of gastroenteritis in the municipality of daimiel. we conducted an investigation to determine the cause or causes of the outbreak and to implement control measures. most of the cases involved young people who visited the municipality's fair.200818261440
extracellular-loop peptide antibodies reveal a predominant hemichannel organization of connexins in polarized intestinal cells.shigella, the causative agent of bacillary dysentery, invades colonic epithelial cells to elicit an intense inflammatory reaction leading to destruction of the mucosa. atp-dependent paracrine signalling induced by connexin (cx) hemichannel opening was previously shown to favor shigella flexneri invasion and dissemination in transfectants of hela cells [g. tran van nhieu, c. clair, r. bruzzone, m. mesnil, p. sansonetti and l. combettes. (2003). connexin-dependent intercellular communication incre ...200818267319
retrograde traffic in the biosynthetic-secretory route.in the biosynthetic-secretory route from the rough endoplasmic reticulum, across the pre-golgi intermediate compartments, the golgi apparatus stacks, trans golgi network, and post-golgi organelles, anterograde transport is accompanied and counterbalanced by retrograde traffic of both membranes and contents. in the physiologic dynamics of cells, retrograde flow is necessary for retrieval of molecules that escaped from their compartments of function, for keeping the compartments' balances, and mai ...200818270728
conserved amphiphilic feature is essential for periplasmic chaperone hdea to support acid resistance in enteric bacteria.the extremely acidic environment of the mammalian stomach (ph 1-3) represents a stressful challenge for enteric pathogenic bacteria, including escherichia coli, shigella and brucella. the hdea (hns-dependent expression a) gene was found to be crucial for the survival of these enteric bacteria under extremely low ph conditions. we recently demonstrated that hdea is able to exhibit chaperone-like activity exclusively within the stomach ph range by transforming from a well-folded conformation at hi ...200818271752
reactive arthritis following culture-confirmed infections with bacterial enteric pathogens in minnesota and oregon: a population-based study.to describe the epidemiology and clinical spectrum of reactive arthritis (rea) following culture-confirmed infection with bacterial enteric pathogens in a population-based study in the usa.200818272671
immunogenicity and efficacy of highly purified invasin complex vaccine from shigella flexneri 2a.development of a subunit vaccine for shigellosis requires identification of protective antigens and delivering these antigens in a manner that stimulates immunity comparable to that induced by natural infection. the shigella invasin complex (invaplex) vaccine is an ion-exchange-purified extract from virulent shigella that consists of lps and several other proteins, including the invasins ipab and ipac. intranasal delivery of invaplex stimulates protective immunity in small animal models for shig ...200818276045
distribution and antibiotic susceptibility of shigella isolates in bangui, central african republic.we conducted a prospective study in four urban health care centres between january 2004 and november 2005 to determine the distribution and susceptibility patterns of shigella strains causing invasive diarrhoea in bangui, central african republic. of the 155 shigella isolated, shigella flexneri (51%) and shigella dysenteriae (30%) were the most common and the most resistant to usual antibiotics, including amoxicillin, sulphamethoxazole-trimethoprim and chloramphenicol. though multi-drug resistan ...200818282240
reaching a consensus on management practices and vaccine development targets for mitigation of infectious diarrhoea among deployed us military forces.this study is part of a research effort to identify and quantify factors related to the cost-effectiveness of a vaccine acquisition strategy to reduce the burden of infectious diarrhoea on us military personnel deployed overseas. where evidence is lacking in the scientific literature, or considerable uncertainty exists, it is often necessary to develop best estimates with ranges of certainty. to this end, a modified 'delphi' survey technique to obtain the best estimates for uncertain parameters ...200818284518
comparative analysis of intestinal microbial community diversity between healthy and orally infected ducklings with salmonella enteritidis by eric-pcr.to analyze the difference of intestinal microbial community diversity between healthy and (s. enteritidis) orally infected ducklings.200818286697
the shf gene of a shigella flexneri homologue on the virulent plasmid paa2 of enteroaggregative escherichia coli 042 is required for firm biofilm formation.enteroaggregative escherichia coli (eaec) is an increasingly important cause of diarrhea in both developing and industrialized countries, and is characterized by strong biofilm formation on the intestinal mucosa. sequencing of the virulent plasmid paa2 of the prototype eaec 042 revealed a cluster of three open reading frames (orfs; shf, capu, and virk) ca. 93% identical to a similar cluster located in shigella flexneri. the function of the first orf shf protein is not known, but the closest well ...200818293034
terpenoid compositions, and antioxidant and antimicrobial properties of the rhizome essential oils of different hedychium species.a phytochemical study of the rhizome essential oils of four different hedychium species was performed by means of gc and gc/ms analyses. h. ellipticum mainly contained 1,8-cineole, sabinene, and terpin-4-ol, while h. aurantiacum possessed terpin-4-ol, para-cymene, and bornyl acetate as the major entities. similarly, trans-meta-mentha-2,8-diene and linalool were noticed in h. coronarium. three different collections (i-iii) of h. spicatum showed amazing differences in the relative contents of thei ...200818293443
diverse antimicrobial killing by enterococcus faecium e 50-52 bacteriocin.an effective bacteriocin was identified and characterized. lactic acid bacteria were screened against campylobacter jejuni. one bacteriocin producer, enterococcus faecium (nrrl b-30746), was studied. the isolate was grown, and the bacteriocin was purified to single-band homogeneity. biochemical traits indicated that the peptide was a class iia bacteriocin, and it was named e 50-52. the bacteriocin had a molecular weight of 3339.7 and an isoelectric point of 8.0. the minimal inhibitory concentrat ...200818293921
association of a factor h mutation with hemolytic uremic syndrome following a diarrheal illness.hemolytic uremic syndrome (hus) takes 2 forms: diarrheal hus and nondiarrheal hus. as its name suggests, diarrheal hus classically follows an enteric infection. the classic infective organism is the escherichia coli o157 serotype, although other bacteria, including shigella species, can produce the verocytotoxin required to cause hus. the usual clinical course is an episode of bloody diarrhea followed by thrombotic microangiopathy and acute renal failure. supportive treatment sees recovery of re ...200818295065
single residue determines the specificity of neutrophil elastase for shigella virulence factors.human neutrophil elastase (ne) is a key host defense protease that cleaves virulence factors of gram-negative bacteria. ne and cathepsin g (cg) are chymotrypsin-like serine proteases with sequence and structural similarities, and both are abundant in neutrophil granules. unlike ne, cg does not cleave virulence factors of enteric bacteria. through structure-function analysis, we identified regions in ne that are essential for cleaving shigella virulence proteins. ne residues at eight different po ...200818295791
geographic analysis of shigellosis in vietnam.geographic and ecological analysis may provide investigators useful ecological information for the control of shigellosis. this paper provides distribution of individual shigella species in space, and ecological covariates for shigellosis in nha trang, vietnam. data on shigellosis in neighborhoods were used to identify ecological covariates. a bayesian hierarchical model was used to obtain joint posterior distribution of model parameters and to construct smoothed risk maps for shigellosis. neigh ...200818296100
socioeconomic risk factors for bacterial gastrointestinal infections.bacterial gastrointestinal infections cause considerable morbidity in industrialized countries, but little is known about socioeconomic factors affecting the risk of infection.200818300694
a five-year antimicrobial resistance pattern of shigella isolated from stools in the gondar university hospital, northwest ethiopia.shigellosis is a global health problem. however, developing countries, where there is poor hygiene and unsafe water supplies, are especially affected. in the last two decades shigella isolates have become increasingly resistant to many commonly used drugs. we investigated the antibiotic susceptibility pattern of shigella isolated from stool specimens processed over five years in the bacteriology laboratory of the university of gondar teaching hospital in northwest ethiopia. stool specimens were ...200818302868
structures of the shigella flexneri type 3 secretion system protein mxic reveal conformational variability amongst homologues.many gram-negative pathogenic bacteria use a complex macromolecular machine, known as the type 3 secretion system (t3ss), to transfer virulence proteins into host cells. the t3ss is composed of a cytoplasmic bulb, a basal body spanning the inner and outer bacterial membranes, and an extracellular needle. secretion is regulated by both cytoplasmic and inner membrane proteins that must respond to specific signals in order to ensure that virulence proteins are not secreted before contact with a euk ...200818304577
the o-polysaccharide of escherichia coli o112ac has the same structure as that of shigella dysenteriae type 2 but is devoid of o-acetylation: a revision of the s. dysenteriae type 2 o-polysaccharide structure.the o-antigen structure of shigella dysenteriae type 2 was reinvestigated using chemical modifications along with high-resolution 2d (1)h and (13)c nmr spectroscopy. the o-antigen was found to contain a pyruvic acid acetal, which was overlooked in an early study, and the following revised structure of the pentasaccharide repeating unit was established: where approximately 70% glcnac residues bear an o-acetyl group at position 3. the o-antigen of escherichia coli o112ac was found to have the same ...200818308298
nlrx1: friend or foe? 200818311173
ipgb1 and ipgb2, two homologous effectors secreted via the mxi-spa type iii secretion apparatus, cooperate to mediate polarized cell invasion and inflammatory potential of shigella flexenri.type iii secretion systems (t3ss) are present in many pathogenic gram-negative bacteria and mediate the translocation of bacterial effector proteins into host cells. here, we report the phenotypic characterization of s. flexneri ipgb1 and ipgb2 mutants, in which the genes encoding the ipgb1 and ipgb2 effectors have been inactivated, either independently or simultaneously. like ipgb1, we found that ipgb2 is secreted by the t3ss and its secretion requires the spa15 chaperone. upon infection of sem ...200818316224
saccharomyces boulardii interferes with shigella pathogenesis by postinvasion signaling events.saccharomyces boulardii is gaining in popularity as a treatment for a variety of diarrheal diseases as well as inflammatory bowel disease. this study was designed to examine the effect of this yeast on infection by shigella flexneri, a highly infectious and human host-adapted enteric pathogen. we investigated key interactions between the bacteria and host cells in the presence of the yeast in addition to a number of host responses including proinflammatory events and markers. although the presen ...200818032477
activities of the frog skin peptide, ascaphin-8 and its lysine-substituted analogs against clinical isolates of extended-spectrum beta-lactamase (esbl) producing bacteria.extended-spectrum beta-lactamase (esbl)-producing gram-negative bacteria are becoming increasingly prevalent and their antibiotic resistance necessitates novel therapeutic intervention. ascaphin-8 is a cationic alpha-helical peptide that shows broad-spectrum antibacterial activity but is also toxic to human erythrocytes (lc(50)= 55 microm). this study assesses the activity of ascaphin-8, and a series of l-lysine-substituted analogs, against a range of clinical isolates of esbl-producing bacteria ...200818068868
quinolone resistance among shigella spp. isolated from travellers returning from india.among 200 isolates of shigella from patients with travellers' diarrhoea, 12 isolates (four isolated in 1995-2000 and eight in 2001-2004) exhibited quinolone resistance. nine of these isolates originated from india. these resistant isolates had at least one amino-acid substitution in gyra. quinolone resistance is increasing in shigella spp. causing travellers' diarrhoea, and particularly among isolates causing diarrhoea in travellers returning from india.200818076667
isolation and purification of enterocin e-760 with broad antimicrobial activity against gram-positive and gram-negative bacteria.strain nrrl b-30745, isolated from chicken ceca and identified as enterococcus durans, enterococcus faecium, or enterococcus hirae, was initially identified as antagonistic to campylobacter jejuni. the isolate produced a 5,362-da bacteriocin (enterocin) that inhibits the growth of salmonella enterica serovar enteritidis, s. enterica serovar choleraesuis, s. enterica serovar typhimurium, s. enterica serovar gallinarum, escherichia coli o157:h7, yersinia enterocolitica, citrobacter freundii, klebs ...200818086839
systemic pharmacokinetics of rifaximin in volunteers with shigellosis.rifaximin is an oral antibiotic indicated for treatment of traveler's diarrhea. rifaximin pharmacokinetics were evaluated in individuals challenged with shigella flexneri. peak plasma rifaximin concentrations were low after nine consecutive doses, and no accumulation was observed. rifaximin serum levels were minimal and similar to those previously reported in studies of healthy volunteers.200818086855
antimicrobial activity of an endophytic xylaria sp.yx-28 and identification of its antimicrobial compound 7-amino-4-methylcoumarin.an endophytic xylaria sp., having broad antimicrobial activity, was isolated and characterized from ginkgo biloba l. from the culture extracts of this fungus, a bioactive compound p3 was isolated by bioactivity-guided fractionation and identified as 7-amino-4-methylcoumarin by nuclear magnetic resonance, infrared, and mass spectrometry spectral data. the compound showed strong antibacterial and antifungal activities in vitro against staphylococcus aureus [minimal inhibitory concentrations (mic) ...200818092158
phenotypic and molecular characterization of tem-116 extended-spectrum beta-lactamase produced by a shigella flexneri clinical isolate from chickens.extended-spectrum beta-lactamases (esbls) produced by a clinical isolate of shigella flexneri from chickens were detected with confirmatory phenotypic tests of the clinical and laboratory standards institute, and minimum inhibitory concentrations of several antibacterial drugs against the isolate were determined by the twofold dilution method. the genotype and subtype of the esbl-producing s. flexneri isolate were identified by pcr amplifying of esbl genes and dna sequencing analysis. the result ...200818093137
involvement of rna-binding protein hfq in the post-transcriptional regulation of inve gene expression in shigella sonnei.the temperature-dependent regulation of shigella virulence genes is believed to be accomplished at the transcriptional stage by the regulators virf and inve. several lines of evidence herein described indicate that post-transcriptional regulation of inve expression plays a key role in the temperature-dependent regulation of virulence gene expression: (i) a considerable amount of inve mrna continues to be transcribed under low temperature conditions, where the production of inve protein is tightl ...200818156173
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